It doesn’t influence performance, files installed are only 117 MB, 43 MB to download. It uses a library, so changing or adding objects is fast and easy. Refer to the ReadMe if you want to do so. Download at http://simheaven.com/?page_id=14813

Important: Before downloading and installing all new stuff, please take 5 min and read this post and the linked page to get an idea what you need and what not to get the best performance and user experience for your flights in X-Plane 10. And you get very useful information to get XP10 running smoothly: